Automatic damper control



Dec. 8, 1931; I D SHMND 1,835,907

AUTOMATIC DAMPER CONTROL Filed May ll, 1951 2 Sheets-Sheet l MiraJ/zx/awa M ATTORNEYS Patented Dec. 8, 1931 UNITED STATES AETHUR D.SHILAND, F CLEVELAND, OHIO A TOMATIC DAMPER CONTROL Application filedMay 11, 1931. Serial 110. 536,537.

The ob'ect of this, my present invention, is to provi e an electricallycontrolled automatic draft regulator that will open and close draftdoors on a furnace by steps instead of opening doors wide or shuttingthem tight. The advantage of this invention is that the draft doors areautomatically brought to the exact position required to giverthe properdraft to keep fire burning at a predetermined intensity as shown andcontrolled ona scale. This is a decided advantage over the up and downcondition of a fire as sometimes regu lated.

Also by certain mechanical changes this invention can be made to operateon changes in pressure of air, gas, water, etc., and made to control avalve, a speed regulator on a motor, etc.

The invention will be fully and comprehensively understood from aconsideration of the following detailed description when read inconnection with the accompanying drawings which form part of theapplication, with the understandin however, that "the improvement iscapa 1e of extended application and is not confined to the exact showingof the drawings nor to the precise construction described and,therefore, such changes and modifications may be made therefrom as donot affect the spirit of the invention nor exceed the scope thereof asexpressed in the appended claims.

In the drawings V Figure 1 shows the installation of the improvement ona furnace to control front draft door only. Other dampers on furnace canbe operated at same time if required, by proper use of chain and ulleys.

Figure 2 shows inventlon installed to operate draft on a furnace. Figure3 is a face view of a slightly modified form of the thermostatic means.

Figure 1 is a side elevation thereof with parts in section. j v In thedrawings the numeral 1 designates a furnace, and 2 the cold air inletduct arranged below the grate and communicating with the ash pit of thefurnace. Either in or in close proximity to the fron of the furnace 1 Ifix an upstanding bracket 3. The bracket has an outer vertical arm 4 towhich is fixed a body member in the nature of a plate 5. The plate 5, onits outer face has at its top a heat degree scale 6 and on the outerface of the plate 5 below the scale Gthere is arranged a fiat arm 8. Thebracket and the plate 5 provide a frame and will be hereinafter referredto as such. The plate 8 has on its outer face an indicator mark 9 toregister with any of the degree marks on the arched scale 6. Below theindicator mark 9 there is fixed on the arm 8 a bearing nut 10 that hasscrewed therethrough a bolt 11. The bolt passes through a bearing 12that is secured on the outer face of the frame by a bolt or screw 13.The outer and non-threaded end of the bolt is headed, as at 14, and thebolt has fixed thereon spaced enlargements in the nature of stopelements 15 to contact with the opposite sides of the bearing 12 andthereby prevent the longitudinal movement of the bolt. The bolt may beadjusted to bring the degree mark 9 opposite any one of the degree markson the scale 6.

Having one of its ends secured to an insulating block 16 on the lowerface of the arm 8 there is one end of an arched laminated spring 17. Thespring 17 is in the nature of a thermostatic member and the second andlower end thereof is fixed in a contact lug 18 that extends downwardlyand over the outer face of the segmental plate or member 19 ofinsulating material. The member 19 is pivotally secured, as at 20, tothe frame. At the opposite sides of the contact lug 18 there are fixedon the segmental plate 19 other lugs 21 which have threaded openingstherethrough for the reception of the shanks of headed screws 22 and 23,respectively, and the said screws are also .in the nature of contacts.Fixed to and extending laterally from the lower end of the segmentalmember 19 there is an arm 24 which has an outer eye end to which isattached one of the end links of a chain or like flexible element 25which is also attached to the hinged damper 2 of the furnace 1. i

The numeral 26 Y designates a shelf that may be arranged in closeproximity to the furnace 1. This shelf affords a support for an electricmotor 27. The motor is of the series type and, therefore, is reversiblein operation. The shaft 28 of the motor, in th1s instance, comprises anelongated member that is guided in upstandi spaced'bearings 29 supportedon the shel 26. The portion of the shaft betweenthe'bearings .29 isthreaded and the said threaded portion is screwed through a threadedopening in an m u standin arm 30 formed on the inner end 7 o alongltudinally extending rod 31 that passes through a bearing opening inthe outer bearin 29. The outer end of the rod is forme with an eye towhich is attached one end of a cable 32, the said cable being trainedover a grooved wheel 33 and is directed downwardly and has it second endsecured to the eye on the end of the arm 24. Wires connected to thehouse current are indicated in'Figure 2 by the numerals 34 ment with theouter faces of the fixed con- 35 tacts 38- and 39, respectively. Theoffset end 30 of the rod 31 has a non-threaded opening therethrough forthe passage of a rod 44 whose inner end is headed, as at 45,- and thesaid head is arranged between the spring 40 contact members 42 and 43.Adjustably fixed on the rod 44 there are spaced stop members 46 and 47,respectively, the samebeing arranged in the opposite sides of theofifset end orarm 30 of the rod 31. The rods 31 and 44 comprise thecircuitbreaker of the improvement and the circuit breaker is operated bythe turning of the shaft 28 of the motor 27.

. The operator adjusts the bolt or .screw 11 to bring the mark 9 on theplate 8 opposite any one of the degree marks on the scale 6 to accordwith the heat temperature desired in the house. This adjustment changesthe relative position of-the bi-m'etal" spring 17 and the contact 18thereon with respect to the v contacts 22.and 23. As the fire in thefurnace dies down and the laminated thermostatic spring 17 is permittedto cool, thespring will ,to'break contact between 18 and 23, stoppinginto spring switches or motor and together with the chain 25 to open thedraft door 2 to a slight degree so that the fire in the furnace will beincreased. However, if the furnace gets colder and more draft is neededthe same operation is repeated until the draft 2 is wide open and theturning of the motor shaft will bring the arm or offset end of the rod31 against the contact 46, thereby imparting longitudinal movement tothe rod 44 to cause the head 45 thereof to engage with the spring switchor contact 43, breaking the circuit and stopping the motor. The pullupon the cable 32 and the chain 25 is not suflicient to swing thesegment 19 to bring the contact 18 into en- 30 gagement with the contactscrew 22, but when the combustion in the furnace increases tea degreethat will cause the thermostatic laminated spring 17 to expandthecontact 18 is brought against the contact screw 22 andvthe damper dropsa trifle which swings the seg-.

mental member 19 to bring the contact screwv 22 away from the contact 18so that the motor will be stopped. When the contact 18 engages with thecontact screw 22 the motor is operated in a reverse direction to thatprevi- 1 ously described which causes the screw-shaft 1 28 to move therod 31 to bring its offset end or arm 30 against the stop 47 and tofurther move the rod 44 to cause the head 45 to engage with the springcontact 42 and to bring the same away from the fixed contact 39 which,of course, breaks the circuit and stops the motor. Thus it will be seenthat the device is entirely automatic in operation.

' The heat may be regulated by a remote control. The control includes aheat degree scale 48, a'rack 49 to one side on the outer face thereof, aheaded element 50 having a stem to bereceived between the teeth of therack and carrying an indicator finger 51 to be disposed opposite any ofthe degree marks on the scale 48. The finger has attached thereto acable 52 and this cable is connected to an arm 53 that extends from aheaded member 54. The member 54 isround in plan and is pivoted, as at55, to the plate 5 and is also pivoted to the arms 8, as at 7. Thebearing 10 holds the upper end of the arm 8 steady so that movement ofthe pivot point 7 will, at the same time, move the lower portion of arm8 and also the contact 18. Thus should .to the left 4 inch by means ofthe arm 53,

then the whole arm 8 will be in a position one-fourth inch to the leftof its first position and the contact 18 will also be one-fourth inch tothe left of its original position. After the device is adjusted theoperation of the control arm 53 takes care of any changes that may berequired. The insulated segment 19 is controlled in its swingingmovement the arm 24-which is in turn controlled'by thicable 32 con- 9 ispivotally secured on the plate in thev same manner as the plate 8 issecured to the plate 5, and to the lower end of the plate 8 there isconnected the arm 53 similar to the arm 53. The plate 8' has its upperedge notched, as at 56, and received in this notch there is a pin 57carried by a cutter arm or finger 58 that is pivotally secured to theplate 5. To the outer face and adjacent to the upper end of the plate 8'there is fixed an insulating block 16"v on whose outer and angle endthere is secured an arched laminated spring 17. The thermostatic spring17 has attached to its free end the upper and round ed portion of 9.depending arm 59 that carries a contact lug adjustable contacts 22and'23 on the segmental plate'19'. Thesegmental plate 19' is pivoted, asat 20', to the plate 5 and carries on its lower end the arm 24. Theparts just described are practically similar and for the same purpose asthose previously described. Having described the invention, I claim:

1. In an automatic damper control, a reversible electric motor wired toa source of electricity, a circuit breaker, a rod movable longitudinallyby the motor and operable in such movement to move the circuit breakerwhen the rod has nearly reached the limit of its longitudinal movementin two directions, a pair of fixed contacts wired to the fields of themotor, movable switches in the path ofengagement-with the circuit,breaker engaging such contacts, a pivoted segment having adjustablecontacts thereon wired respectively to the switches, an arm extendingfrom the segment, a flexible element connected to the damper of afurnace. and to the arm of the rod, guide means for the flexibleelement, a thermostatic spring having one end fixed and its other endprovided with a contact which is arranged between the adjustablecontacts and the segment and said spring contact and wire being wired tothe contacts on the segment.

2. In an automatic damper control, a reversible electric motor wired toa source of electricity, a circuit breaker, a rod movable longitudinallyby the motor and operable in such movement to move the circuit breakerwhen the rod has nearly reached the limit of its longitudinal movementin two directions, a pair of fixed contacts wired to the fields of themotor, movable switches in the path of engagement with the circuitbreaker engaging such contacts, a pivoted segment having adjustablecontacts thereon wired respectively to the switches. an arm extendingfrom the segment, a flexible element connected to the damper ,ofafurnace and to the arm of the rod, guide meansfor the flexible element,a

18' movable between thethermostatic spring having one end fixed and itsother end provided with a contact, which is arranged between theadjustable contacts on thesegment and said spring contact and wire beingwired to the return wire of the circuit, a swingable plate on which thefixed end of the thermostatic spring is secured, and adjustable meansfor swinging and holding the plate at determined angles. 3. In anautomaticdamper control, a reversible electric motor wired to a sourceof the motor,'movable switches in the path of engagement with thecircuit breaker engaging such contacts, a pivoted segment havingadjustable contacts thereon wired respectively to the switches, an armextending from the segment, a flexible element connected to the damperof a furnace and to the arm of the rod, guide means for the flexibleelement, a thermostatic spring having one end fixed and its other endprovided with a contact which is arranged between the adjustablecontacts on the segment and said spring contact and wire being wired tothe return wire of the circuit, a swingable plate on which the fixed endof the thermostatic spring is secured, said plate being of insulatingmaterial and having an indicating mark thereon, a heat degree scaleopposite the indicator mark, and ad justable means for swinging theplate to bring the mark thereon opposite any of the heat degree scalemarks.'

4. In an automatic damper control, a reversible electric motor wired toa source of electricity, a circuit breaker, a rod movable longitudinallyby the motor and operable in such movement to move the circuit breakerwhen the rod has nearly reached the limitof its longitudinal movement intwo directions, a pair of fixed contacts Wired to the fields of themotor, movable switches in the path of segment, a flexible elementconnected to the damper of a furnace and to the arm of the rod, guidemeans for the flexible element, a thermostatic spring having one endfixed and its other end provided with a contact which is arrangedbetween the adjustable contacts on the segment and said spring contactand wire being wired to the return wire of the circuit, a swingableplate on which the fixed end of the thermostatic spring is secured, andadjustable means for swinglng and holding the plate at determinedangles, said means including an arm fixed on the plate, a degree scale,a mark opposite the scale and a pointer 13o element directed toward thescale, an operat-' ing handle for the pointer element having a partengageable with the rack and a flexi 1e connection between the pointerelement and 5 the arm. i

5. A reversible electric motor having a field wire connected thereto, ascrew shaft operated by the motor, bearings for the shaft, a rod havingan angle end threadedly engaged b the shaft, a headed member movablethroug the bearings and likewise movable through the angle end of therod, adjustable stop elements on the member and said headed membercomprising a circuit'breaker, fixed contacts wired to the fields of themotor, oppositely disposed swingable switches engaging the contacts andsaid switches being in the path of engagement with the head of thecircuit breaker, when the latter is moved by the b rod in either of twodirections, a pivotally supported segmental plate of insulatingmateri'al, adjustable contacts thereon wired to therespective switchmembers,'anarm extending from the segment, a pivotally supported plateof insulating material, a coiled thermostatic spring having one endfixed to the plate and its second end provided with a contact which isarranged between the adjustable contacts on the segment and the springcontact being connected to the feed wire, said plate having a mark onthe upper end thereof, a heat degree scale opposite the said end of theplate, a means located adja-' cent to the plate or located remote fromthe plate for swinging the plate to arrange the mark thereon oppositeany of the marks on the heat scale, flexible elements connected to therod, the arm and to the draft door of a furnace and guides for saidelements. 40 In testimony whereof I afiix my signature. ARTHUR D.SHILAND.

